0.1.1: Crash fix and initial menu changes

Crash fix:

• Fixed issue where game could crash when displaying end-of-level leaderboard.

Bug fixes:

• Leaderboard now displays correctly regardless of how many entries there are.

• Leaderboard now correctly displays scores around the player, if lower on the leaderboard.

• Pause menu does not come up over leaderboard.

• Fixed other flow issues in menus.

General changes:

• Moved initial menu to the menu scene (displays on bike trail).

• Darkened part of the vehicle select screen to make stats clearer.

Known issues:

• Game window does not fill the screen, only on first launch.